Turning the tide in stroke recovery: IGF-2 as a driver of neuroprotection, angiogenesis and neurogenesis.

Your advisors incompetently didn't know of all this earlier research AND DIDN'T KNOW OF YOUR RESPONSIBILITY TO CREATE STROKE REHAB PROTOCOLS FROM THAT?

I don't care if you are still a student, the real world requires creation of EXACT REHAB PROTOCOLS, at least if you are being trained correctly!

angiogenesis (143 posts to April 2011)

neuroprotection (333 posts to March 2011)

neurogenesis (635 posts to September 2010)

 Turning the tide in stroke recovery: IGF-2 as a driver of neuroprotection, angiogenesis and neurogenesis.

Authors:	ALDERS, Lotte
Advisors:	Bronckaers, Annelies Wolfs, Esther
Issue Date:	2026
Abstract:	Stroke remains one of the leading causes of death and long-term disability worldwide, and despite advances in acute care, therapeutic options remain severely limited. The currently approved treatments, including reperfusion therapies with intravenous thrombolysis or endovascular thrombectomy, are constrained by narrow therapeutic windows, strict eligibility criteria, and limited accessibility. As a result, the majority of patients remain untreated and are left with permanent neurological impairments. This reality underscores the urgent need for new therapeutic approaches that not only preserve brain tissue immediately after stroke but also actively support long-term repair and recovery. Within this context, insulin-like growth factor 2 (IGF-2), traditionally known for its role in fetal growth and development, has emerged as a promising candidate. Unlike IGF-1, IGF-2 remains abundant in the adult brain, suggesting it may play a role in central nervous system maintenance and repair. This dissertation has four main aims to advance stroke research: 1) to evaluate the neuroprotective effects of IGF-2 and Des(1-6)IGF-2 on infarct size, 2) to investigate their impact on post-stroke neuroinflammation, 3) to examine their role in promoting angiogenesis in vitro and in ovo, and 4) to assess their effects on neural stem cell proliferation and migration. The overall goal is to clarify how IGF-2 and its analogs contribute to brain protection and brain repair.
Document URI:	http://hdl.handle.net/1942/48558

From Evidence to Practice: Efficacy and Implementation of High-intensity Locomotor Training for Stroke Rehabilitation

 And your doctorate advisors didn't inform you of problems with HIT?  You will 100% guarantee that HIT will not cause a stroke? By verifying that your aneurysms will not blow out?

Do you really want to do high intensity training?

Because Andrew Marr blames high-intensity training for his stroke. 

Can too much exercise cause a stroke?

From Evidence to Practice: Efficacy and Implementation of High-intensity Locomotor Training for Stroke Rehabilitation

Tapp, Annie

ORCID® Identifier

http://orcid.org/0000-0003-2314-1140

Permalink:

http://rave.ohiolink.edu/etdc/view?acc_num=ysu1733749623360122

Abstract Details

Year and Degree

2024, Doctor of Philosophy in Health Sciences, Youngstown State University, Department of Graduate Studies in Health and Rehabilitation Sciences.

Abstract

This dissertation investigates the efficacy and real-world implementation of high-intensity locomotor training (HIT) for stroke patients during inpatient rehabilitation. The project was guided by three specific aims: (1) to evaluate the strength of the evidence supporting HIT for improving ambulation outcomes, (2) to determine whether clinicians can replicate these results in a real-world setting, and (3) to identify the barriers and facilitators to implementing HIT in inpatient rehabilitation facilities (IRFs) across the United States. The first study, a systematic review, confirmed that HIT is more effective than usual care in improving gait speed and endurance at discharge for patients with stroke, with moderate effect sizes on meta-analysis. The second study, a retrospective analysis of a clinician-initiated HIT project, revealed challenges in replicating these outcomes in a real world setting, possibly due to low implementation fidelity suggesting that a minimum threshold of fidelity may be necessary to see unit-wide improvements. The third study used a Delphi survey approach to explore the experiences of clinicians implementing HIT in IRFs. While several facilitators to HIT adoption were identified, a notable barrier was insufficient time, consistent with barriers to evidence-based practice reported in other rehabilitation disciplines. Despite favorable conditions, less than half of surveyed clinicians reported using HIT daily, indicating ongoing challenges. HIT is an effective intervention for improving walking ability in patients post-stroke during inpatient rehabilitation. Future research should focus on addressing key barriers, exploring optimal dosing strategies and fidelity targets, and developing interdisciplinary approaches to increase the widespread adoption of HIT across the continuum of care in stroke rehabilitation.

Committee

David Griswold, PhD (Committee Chair)
Kenneth Learman, PhD (Committee Member)
Susan Linder, DPT (Committee Member)
Nancy Landgraff, PhD (Committee Member)

Pages

123 p.

Assessing Ankle Proprioception using a Novel Robotic Device: Generalizability, Parameter Sensitivity, and Predictive Power for Stroke Rehabilitation

 'Assessments' are completely useless unless directly used to map to EXACT PROTOCOLS that fix the deficit! I'm not going to read this, that is your doctor's and therapist's responsibility!

 Assessing Ankle Proprioception using a Novel Robotic Device: Generalizability, Parameter
Sensitivity, and Predictive Power for Stroke Rehabilitation

Permalink
https://escholarship.org/uc/item/5b03k043
Author
Johnson, Christopher
Publication Date
2024
Peer reviewed|Thesis/dissertation
eScholarship.org Powered by the California Digital Library
University of California

 

154 pages at link

Post-stroke Gait: Implications for Future Customizable Rehabilitation ApproachesCustomizable Rehabilitation Approaches

Unless this monitoring leads to EXACT PROTOCOLS to recover from the deficits in your walking, I can't see much use for this.  The mentors failed this research fellow by not specifying the proper outcome.

 Post-stroke Gait: Implications for Future Individuals with Post-stroke Gait: Implications for Future Customizable Rehabilitation Approaches Customizable Rehabilitation Approaches

To the Graduate Council:
I am submitting herewith a dissertation written by Azarang Asadi entitled “Motor
Control Quantification and Necessary Improvements for Individuals with Post-stroke
Gait: Implications for Future Customizable Rehabilitation Approaches.” I have
examined the final electronic copy of this dissertation for form and content and
recommend that it be accepted in partial fulfillment of the requirements for the degree
of Doctor of Philosophy, with a major in Biomedical Engineering.
Jeffrey A. Reinbolt, Major Professor
We have read this dissertation
and recommend its acceptance:
Zhenbo Wang
Emre Demirkaya
Michael A. Langston
Accepted for the Council:
Dixie L. Thompson
Vice Provost and Dean of the Graduate School
(Original signatures are on file with official student records.)Motor Control Quantification and
Necessary Improvements for Individuals with Post-stroke Gait:
Implications for Future Customizable Rehabilitation Approaches
A Dissertation Presented for the Doctor of Philosophy Degree
The University of Tennessee, Knoxville
Azarang Asadi
May 2024© by Azarang Asadi, 2024
All Rights Reserved.
To my mother, Mahbobeh, for all the support and sacrifices, and my sister, Mehregan,
for always believing in me.
Acknowledgements
I would like to thank and express my utmost gratitude to my advisor, Dr. Jeffrey
A. Reinbolt. His guidance and mentorship made this work possible and carried me
through all stages. His continuous support and patience made me feel competent,
and I am eternally grateful for being a graduate student in his research group.
I would like to thank the members of my dissertation committee, Dr. Michael
Langstong, Dr. Zhenbo Wang, and Dr. Emre Demirkaya for their time and valuable
comments. Their critical feedback and knowledgeable insights challenged me to
become a better scientist.
My appreciation extends to my fellow colleague at Reinbolt Research Group,
especially Ashley Rice who helped me tremendously with OpenSim and MATLAB.
I would like to extend my deepest gratitude to my mother. Mom, your selflessness
and sacrifices have been the bedrock of my academic journey. This accomplishment is
as much yours as it is mine, and I dedicate it to you with all my love and appreciation.
I am profoundly grateful to my sister whose enduring support, encouragement,
and belief in me have been a constant source of strength throughout my academic
journey. Her unwavering faith in me has been instrumental in achieving this milestone
and I am deeply thankful for her love and support.
I would like to thank my family and friends, especially Minou Attaei. Her support
and encouragement throughout this journey have been invaluable, and I am very
fortunate to have such a wonderful friend. Heartfelt thanks to my friend, Nobahar
Shahidi, for the support and guidance. I am grateful to have such a caring friend.
ivLast but not the least, I would like to give special thanks to my sweet dear feline
companions, Luna and Mah Banoo. Without their emotional support, none of this
work would have been possible. To my beloved cats, thank you for being my furry
writing companions throughout this journey.

Abstract

Although often taken for granted, walking is an extremely complex motor skill that
requires sensory inputs, neural communication, advanced control strategies, and
coordination of the muscles and joints. Electrical signals traveling from the brain
to the muscles are transformed to mechanical forces to achieve desired motion. A
stroke damages the central nervous system and neural pathways, limiting the ability
of survivors to walk. Walking speed is significantly decreased and asymmetrical
walking patterns emerge. A crucial component of stroke rehabilitation is gait training,
a therapeutic intervention to help individuals to improve their walking ability, as
walking is essential for functional independence and long-term survival.
Walking speed is often used as a gold standard for assessing the walking
capabilities of stroke survivors, however, it’s important to note that a higher walking
speed may not always indicate true recovery and may be a result of compensatory
mechanisms. Monitoring the neurological impairment can improve our understanding
of the walking disorder associated with stroke, guide the treatment according
to patient’s specific needs, and contribute to development of new rehabilitation
paradigms to improve the neuromuscular impairment.
In this work, we aim to establish a computational framework for real-time
monitoring of walking ability of stroke survivors at a neural level, applicable for
both gait laboratories and real-world settings. Additionally, we will investigate
the capability of using such framework to improve the rehabilitation techniques for
maximizing motor control complexity. We unite biomechanical modeling, simulations,
vistatistics, and machine learning to achieve the goals of this research. First,
we will investigate various quantitative measures of walking to understand their
association with neurological impairment, and assess their potential for neuromuscular
impairment monitoring purposes. Second, we will examine the utility of wearable
sensors for assessing motor control complexity of stroke survivors during walking, with
the aim of making assessments accessible beyond the gait laboratory. Lastly, we will
investigate the muscle activity changes corresponding to motor control improvements
of stroke survivors, in order to identify new rehabilitation paradigms to enhance the
motor control complexity of post-stroke gait.

Disturbed Body size perception: acute versus chronic stroke patients with hemiparesis

You can ask your doctor about this 55 page dissertation and the applicability to your recovery.

 Disturbed Body size perception: acute versus chronic stroke
patients with hemiparesis

The role of platelets in hepatic ischemia reperfusion injury in mice

There might be something in here but I can't tell

 The role of platelets in hepatic ischemia reperfusion injury in mice

Doctoral thesis for a doctoral degree
at the Graduate School of Life Sciences,
Julius-Maximilians-Universität Würzburg
Section Biomedicine
submitted by
Carina Gross
from Gronau/Westf.
Würzburg, 2020

Summary

Platelets are the second most abundant blood cells and their main function is maintenance of vascular integrity. In addition, platelets are increasingly recognized as cells with immune functions, as they participate in the recruitment of immune cells and modulate the progression and severity of an immune response. So-called lipid mediators, which are – besides other cells– released by activated platelets, influence the immune response. LTB4 is one of these potent lipid mediators and is able to activate neutrophils and induce their infiltration into injured tissue. In order to investigate the involvement of platelets in inflammatory processes, a murine model of hepatic ischemia reperfusion injury as well as confocal intravital microscopy of the liver were established. Both methods were used to analyze the influence of platelets on the inflammation that follows sterile liver inflammation. We found platelet function to be unaltered after three hours of reperfusion and platelet aggregation to be irrelevant for the outcome of hepatic ischemia reperfusion injury. However, a strong impact of the GPIb-vWF axis could be observed, as antibody mediated blockade of GPIb as well as vWF-deficiency significantly reduced liver damage markers and decreased neutrophil infiltration. GPIb-IL-4R mice were used to exclude the possibility that the protective effects of the anti-GPIbα antibody treatment (p0p/B) results from something else than blocking GPIb. Furthermore, the slope of neutrophil infiltration was decreased in p0p/B-treated mice, leading to overall decreased neutrophil numbers in the liver after three hours of reperfusion. Blockade of the integrin IIbβ3, however, showed no reduction in neutrophil infiltration into the post-ischemic liver, in line with unaltered liver damage. To study the role of leukotriene B4, conditional and constitutive knockout mice for the LTA4 hydrolase, which catalyzes the last step in LTB4 synthesis, were generated. Lta4h deficiency did not affect general platelet functionality in hemostasis and thrombosis. Interestingly, Lta4h mice were not protected from cellular damage following hepatic ischemia, despite lower neutrophil numbers in the post-ischemic liver. Intravital microscopy of the pancreas was established and revealed increased CD4+T cell numbers in GPVI-deficient animals compared to WT controls in line with the pre-diabetic phenotype of Gp6 mice that was revealed in Grzegorz Sumara’s group. Furthermore, platelet ‘behavior’ in pancreatic islets was observed following glucose injection. We found a high number platelets adherent islet sinusoids under basal conditions and rolling/decelerating of platelets following glucose injection. was accompanied by temporary sinusoidal constriction and stop of the blood flow. This phenomenon was not observed in control settings (injection of PBS, insulin or L-glucose). 

 

IV 

 

In a side project, which was carried out jointly with Tobias Heib, a side by side comparison of the classical syringe-based flushing and the centrifugation-based spinning method to isolate murine bone marrow was conducted. Flow cytometry revealed no differences in the distribution of hematopoietic stem cells and immune cells and functional analysis with primary and cultured megakaryocytes (MKs) showed comparable results in all conducted assays. Thus, our data demonstrated that the faster and more efficient spinning method can be used for the isolation of bone marrow cells.

More than Clearing the Clutter: The Imperative Role of Efferocytosis in Repair and Immune Reprogramming in the Damaged Nervous System

230 pages for your doctor to consume.

More than Clearing the Clutter: The Imperative Role of Efferocytosis in Repair and Immune Reprogramming in the Damaged Nervous System

 by Lucas D. Huffman A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Neuroscience) in the University of Michigan 2021 Doctoral Committee Professor Roman J. Giger, Chair Associate Professor Catherine A. Collins Professor Gabriel Corfas Professor Daniel J. Goldman Professor Benjamin M. Segal Lucas D. Huffman lucashu@umich.edu ORCID iD: 0000-0002-7779-086X © Lucas D. Huffman 2021

 

The Use of VR-Assisted Therapy in Post-Stroke Upper Limb Rehabilitation: A Systematic Review and Meta-Analysis

Your doctor can read the 9 pages of this dissertation and see what needs to be changed in your upper limb protocols to get to 100% recovery. 

The Use of VR-Assisted Therapy in Post-Stroke Upper Limb Rehabilitation: A Systematic Review and Meta-Analysis

by Kevin Sprotte 

Advisor: Dr. Henry Sacks 

Background: Virtual Reality (VR) presents an exciting new method for upper limb rehabilitation that may provide an inexpensive and engaging at-home regimen for physical therapyin patients suffering a post-stroke motor deficit. Methods: This study is a systematic review and meta-analysis that included randomized, controlled trials that compared VR therapy to traditional physical therapy in patients with a motor deficit post-stroke. We searched the MEDLINE, EMBASE, and SCOPUS databases for relevant studies that used the Fugl-Meyer Assessment (FMA) or the Box and Block Test (BBT) as outcomes of motor function. Results: 1,187 studies were obtained from the literature search, of which 25 were included in this review. Meta-analysis showed a significantly greater improvement in FMA scores among those who received VR therapy compared to conventional therapy. The difference in BBT improvement was not found to be significant

The sooner the better?!: Providing ankle-foot orthoses in the rehabilitation after stroke

The more important question to answer is; What is the protocol to wean yourself off the AFO? If your doctor and therapists don't know that answer you need to fire them. 

The sooner the better?!: Providing ankle-foot orthoses in the rehabilitation after stroke

Abstract   In stroke, the blood circulation in the brain is affected, being either ischemic or hemorrhagic. Depending on the location of the lesion, the effects can widely vary. Initial walking function is limited in approximately two-third of the patients. A “drop-foot”, the inability to dorsiflex the foot, is estimated to be present in 20-30% of the people after stroke and causes foot-clearance problems during swing phase and also affects initial contact at the start of the stance phase. Insufficient foot-clearance is associated with high risks for stumbling and falling. Ankle-foot orthoses (AFOs) are commonly used to correct drop-foot after stroke and are reported to improve mobility and balance, ankle kinematics, walking speed, self-confidence and fear of falling after stroke. However, most studies reporting on AFOs after stroke included chronic stroke patients who were already provided with AFOs in daily life and were able to walk independently. The general aim of this thesis was to increase the understanding of the effects of providing AFOs early after stroke. The EVOLUTIONS-project was conducted, including a randomized controlled trial in which the effects of AFO-provision on two different time points in the rehabilitation after stroke were studied. Subjects were included within six weeks after stroke and randomized for AFO-provision at inclusion of the study (in week 1) or eight weeks later (in week 9). The subjects were provided with one of three commonly used types of off-the-shelf, non-articulated AFOs with variability in stiffness. Subjects randomized for delayed provision did not use an AFO in the first eight weeks of the study. Subjects were studied up to 17 weeks with (bi)weekly intervals. Follow-up measurements up to 26 and 52 weeks were included. Measurements included functional outcomes related to balance, walking and activities of daily life. Furthermore, gait kinematics of the affected lower limb, muscle activation patterns of the tibialis anterior muscle, and falls and near falls were studied. Results showed positive effects on functional outcomes, both when AFOs were provided early or delayed. After 26 weeks no differences in functional outcomes were found between both groups. However, the results suggest that early provision results in better outcomes in the first 11-13 weeks of the study. Ankle dorsiflexion significantly improved directly after AFO-provision, changing the ankle from a plantarflexion into a dorsiflexion angle at initial contact, foot-off and during swing. These results were obtained regardless of AFO-provision early or delayed after stroke. In general, knee, hip and pelvis angles did not change directly after AFO-provision. After 26 weeks, no differences in kinematics in any of the joint angles were found between the two groups. These kinematic results indicate that AFOs improved drop-foot, but did not influence movement patterns around pelvis and hip. Previous literature suggested that AFO-use might increase muscle weakness, and thereby could impede recovery. Therefore, the effects of AFO-provision on muscle activity of the tibialis anterior were assessed. Results showed that AFO-use reduced muscle activity during swing within a measurement session, compared to walking without AFO. However, 26 weeks use of an AFO did not affect tibialis anterior muscle activity during walking without AFO. Again, early or delayed AFO-provision did not affect the results. These results indicate that there is no need to fear negative consequences on tibialis anterior activity because of long-term AFO-use (early) after stroke. In addition, the effects on the occurrence and circumstances of (near) falls were studied using diaries. In case of an incident, the location, performed activity, possible injuries and whether the AFO was used. We found that subjects in the early group, who had already been provided with AFOs, fell significantly more often in the first eight weeks of the study, compared to the delayed group who had not yet been provided with AFOs. The majority of the falls in the early group in week 1-8 occurred without wearing the AFO. Falls mainly occurred during transfers and standing, during activities related to getting in/out bed, toileting and showering. The majority of the subjects had not yet reached an independent ambulation level at the time of the fall (Functional Ambulation Categories ≤3) and had low balance levels (Berg Balance Scale <45). This highlights the need for careful instructions from clinicians and nursing staff to patients and their relatives, and to emphasize the potential risks of performing activities without the proper assistance, especially in situations without wearing the AFO and without independent walking ability. Summarizing, the results of the current thesis show that clinicians, together with the patient, can decide what they value most in when making the decision on when to commence with AFO-provision. AFOs were found to improve drop-foot regardless of the timing of AFO-provision after stroke. Early AFO-use is expected to result in higher functional levels earlier in the rehabilitation. Despite potential functional gains in the first period of rehabilitation, early AFO-provision does not lead to higher functional levels after 26 weeks, compared to delayed provision. In addition, early or delayed AFO-provision did not influence pelvis, hip and knee kinematics on the short- or long-term. Therefore, AFOs should be provided to correct the drop-foot, but there is no reason to assume that early AFO-provision will influence the development of compensatory movements around the pelvis and hip in the rehabilitation after stroke. AFO-use reduced muscle activity of the tibialis anterior in swing compared to walking without AFO, when effects were measured within one measurement session. However, no negative effects over 26-weeks were found. Therefore, based on the results of our study, fear of disuse concerning the tibialis anterior does not seem to be a justifiable reason to delay AFO-use in the rehabilitation after stroke. One should be aware that higher numbers of falls were found in case that subjects were provided with AFOs early after stroke. Special attention needs to be made to the specific instructions given regarding AFO-use, since the majority of the falls occurred without wearing the AFO and while subjects were not allowed to ambulate independently. Title The sooner the better?! : Providing ankle-foot orthoses in the rehabilitation after stroke Author Nikamp-Simons, C.D.M. Thesis advisor Buurke, Jaap Hilbert, Rietman, Johan Swanik Publisher Biomedical Signals and Systems Date issued 2019 Access Embargoed Access Reference(s) Stroke rehabilitation, Ankle-foot orthosis, functional outcomes, Gait kinematics, electromyography (EMG), falls Language English Type Doctoral thesis Publisher University of Twente Publication https://research.utwente.nl/en/publications/ec347c8e-bd20-4a... OpenURL Search this publication in (your) library Persistent Identifier urn:nbn:nl:ui:28-ec347c8e-bd20-4a1d-9e0e-3c03922a9501 ISBN 978-90-365-4747-5 DOI 10.3990/1.9789036547475 NBN urn:nbn:nl:ui:28-ec347c8e-bd20-4a1d-9e0e-3c03922a9501 Url https://research.utwente.nl/en/publications/ec347c8e-bd20-4a... Metadata XML Source University of Twente

Post-stroke rehabilitation of hand function based on Electromyography biofeedback

131 pages for your doctor to decipher if anything here will help you recover.

Post-stroke rehabilitation of hand function based on Electromyography biofeedback

Effects of Voluntary Physical Rehabilitation on Neurogenesis In SVZ And Functional Recovery After Ischemic Stroke

So the advisors to this dissertation candidate should followup with human research testing this out. That is the minimum a competent university department should be doing. 

Effects of Voluntary Physical Rehabilitation on Neurogenesis In SVZ And Functional Recovery After Ischemic Stroke

 

Author InfoBalakrishnan, Anuranjani

ORCID® Identifier

http://orcid.org/0000-0002-4407-5165

Social Media

Permalink:

http://rave.ohiolink.edu/etdc/view?acc_num=wright1537186443944433

---

Year and Degree

2018, Master of Science (MS), Wright State University, Microbiology and Immunology.

Abstract

Stroke is the leading cause of long-term disability and 87% of all strokes are due to ischemic strokes. In this current study, we examined whether voluntary physical rehabilitation can influence neurogenesis (measured by Doublecortin) in the subventricular zone and show improved motor functional recovery in 10-12 month female rats after ischemia. We saw a significant increase in the neurogenesis (measured by doublecortin) of all three regions (anterior, middle and posterior) of SVZ in the rehab animals compared to control group when using a two-way variance ANOVA test, although we were unable to see significant differences in paired t-tests of similar regions for control and rehab animals. The control animals showed a significant increase in contralateral functional recovery of 56% with rehab animals displaying a recovery of 23%. These findings suggest that the physical rehabilitation showed increased neurogenesis in the SVZ but did not translate to greater contralateral functional recovery.

Committee

Adrian M. Corbett, Ph.D. (Committee Chair)
Nancy J. Bigley, Ph.D. (Committee Member)
Debra Ann Mayes, Ph.D. (Committee Member)

Pages

88 p.

Subject Headings

Immunology; Neurobiology; Neurosciences; Physiology; Rehabilitation

Keywords

neurogenesis; doublecortin; rehabilitation; ischemic stroke; ipsilateral recovery; contralateral recovery; Montoya Staircase

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APA Citation

MLA Citation

Chicago Citation

Files

Final thesis.pdf (2.31 MB) View|Download

Document number:

wright1537186443944433

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Copyright Info© 2018, some rights reserved. Effects of Voluntary Physical Rehabilitation on Neurogenesis In SVZ And Functional Recovery After Ischemic Stroke by Anuranjani Balakrishnan is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. Based on a work at etd.ohiolink.edu.
This open access ETD is published by Wright State University and OhioLINK.

Using priming to promote neuroplasticity and motor learning post-stroke

In your Aim 1 you already have a high functioning survivor selected, high intensity walking is not normally possible. It took me years to get to that point. 
http://dspace.udel.edu/handle/19716/23718

Author: Li, Xin

Download

Citable URI: http://udspace.udel.edu/handle/19716/23718
Advisor: Morton, Susanne M.; Reisman, Darcy S.
Publisher: University of Delaware
Date Issued: 2018
Abstract: The majority of stroke survivors experience persistent motor impairments even with rehabilitation treatments. An underlying mechanism for this is the decreased motor cortical excitability in the lesioned hemisphere after stroke. Priming techniques, such as acute exercise and transcranial direct current stimulation (tDCS), can increase motor cortical excitability and enhance motor learning in healthy individuals. But whether they have the same effects in people with stroke is unclear. Selective serotonin-reuptake inhibitors, a type of antidepressant medication, can change motor cortical excitability in healthy individuals and in acute stroke survivors. Moreover, they can interact with tDCS, changing the effects of tDCS in healthy individuals. Given that up to 30% of stroke survivors take antidepressant medications, this is an important factor to consider when evaluating the effects of tDCS in stroke. The overall purpose of this dissertation was to investigate the neurophysiological effects of exercise priming and tDCS (with chronic antidepressant intake as a factor), and to investigate the effects of tDCS on locomotor learning in people with chronic stroke. ☐ In Aim 1, we showed that exercise priming, in the form of 5 minutes of high-intensity walking, induced increased motor cortical excitability in the lesioned hemisphere, as measured in a resting upper extremity muscle. This finding is significant because it provides evidence on the effectiveness of a clinically feasible exercise priming paradigm to induce broad excitability changes in the brain. ☐ In Aim 2, we showed that stroke survivors taking antidepressant medications had higher motor cortical excitability in the non-lesioned hemisphere compared to those not on antidepressants. We also found that application of anodal tDCS as a primer over the lesioned hemisphere produced differential effects on excitability in the unstimulated, non-lesioned hemisphere, depending on antidepressant-taking status. In antidepressant-takers, motor cortical excitability in the non-lesioned hemisphere increased, while it decreased compared to sham in those not taking antidepressants. These findings draw attention to the fact that stroke survivors may not respond in the same way to tDCS as healthy individuals, and that antidepressants, and potentially other medications and stroke-related factors, must be considered and their effects investigated before providing tDCS as a clinical treatment. ☐ Finally,
in Aim 3, we showed that anodal tDCS over the lesioned hemisphere did not have any effect on split-belt treadmill locomotor learning and retention in chronic stroke survivors. We speculate that split-belt adaptation may not be sensitive to modulation by tDCS. Future studies should investigate whether tDCS affects other types of locomotor learning. ☐ Overall, this work demonstrates the potential of exercise priming for stroke recovery, and highlights the complexity of tDCS usage in people with chronic stroke. Future studies should focus on how individual differences affect priming in stroke.
URI: http://udspace.udel.edu/handle/19716/23718